[Samba] How to detect active users

[Malte Forkel]

Am 26.07.2011 19:27, schrieb Jeremy Allison:
> On Tue, Jul 26, 2011 at 07:18:15PM +0200, Malte Forkel wrote:
>> Am 26.07.2011 19:08, schrieb John Drescher:
>>> On Tue, Jul 26, 2011 at 1:04 PM, Malte Forkel <malte.forkel at berlin.de> wrote:
>>>> Am 26.07.2011 18:42, schrieb Chris Weiss:
>>>>> On Tue, Jul 26, 2011 at 3:06 AM, Malte Forkel <malte.forkel at berlin.de> wrote:
>>>>>> Currently, I'm not even sure Samba preserves the kind of state
>>>>>> information required to detect the usage scenario  I'm interested in. Is
>>>>>> there any concept of an "open file" in Windows/Samba, after all? May be
>>>>>> it depends on the application used to open the file?
>>>>>
>>>>> yes, it depends on the application.  If the app closes the file and
>>>>> leaves the share, samba honors that.  if the app keeps the file handle
>>>>> open, samba does too.
>>>>
>>>> So an application (like SciTE) might open a file, read and display its
>>>> contents, and close the file while continuing to display it. And in
>>>> contrast, a different application might not close the file while it is
>>>> displaying its contents?
>>>
>>> Exactly.
>>>
>>> John
>>
>> Well, thanks to all of you for your help.
>>
>> In summary then, it looks to me like I won't be able to reliably detect
>> if there is any client out there who would be disappointed if the server
>> shuts down.
> 
> Of course you will ! smbstatus does this as I keep repeating.
> If an application has opened and closed the file and keeps it
> in memory, then the user won't be disappointed if the server
> is shut down, they'll get an IO error on save and have to
> do a "save as" to a local (or other remote) drive.
> 
> If an application keeps the file open (so it's not safely
> stored in memory) then smbstatus will show this and you
> don't shut the server down.
> 
> You seem to think there's some "magic" option that will
> show you client intent, not client activity.
> 
> Client activity is all you need to care about, and smbstatus
> show you this. Doesn't matter if applications are running
> or not, whether that have actual files open is all that
> matters.
> 
> Jeremy.

Well, I guess some people get disappointed more easily than others :-)

I understand that users won't loose any data if the server shuts down
and they "save as" their changes. But having to re-synchronize those
files with those on the server once it is up again is something I'd like
to avoid.

Plus, the open files (from a user perspective) might just be an
indicator that the user would like to use other capabilities of the
server as well. E.g., he might do remote development of an application
on the server using Eclipse on the Windows machine. If I found out that
the server had shut down when I try to compile a new version (implicitly
saving changed files before), I'd be disappointed.

Malte